The National Highway Traffic Safety Administration’s (NHTSA) chief counsel recently interpreted a number of provisions in the Federal Motor Vehicle Safety Standards (FMVSS) as they would apply to Google’s self-driving vehicles (SDV). The tech giant asked NHTSA for its feedback on a variety of topics, including rear-view mirrors and the need for windshields wipers, among others.
Google wants to know how it would certify its self-driving system (SDS) to the FMVSS.
Paul A. Hemmersbaugh, NHTSA’s chief counsel, says the FMVSS were drafted at a time when it was reasonable to assume that motor vehicles would have a steering wheel, accelerator pedal and brake pedal and would be operated by a human driver.
“As self-driving technology moves beyond what was envisioned at the time when standards were issued, NHTSA may not be able to use the same kinds of test procedures for determining compliance. And since the Safety Act creates a self-certification system for compliance, NHTSA’s verification of a manufacturer’s compliance (and thus, the agency’s ability to enforce against non-compliance) is based on our established test procedures,” Hemmersbaugh says.
The chief counsel says that the interpretations offered by NHTSA can be changed or revoked if new facts comes to light.
“As a foundational starting point for the interpretations, NHTSA will interpret driver in the context of Google’s described motor vehicle design as referring to the self-driving system, and not any of the vehicle occupants,” Hemmersbaugh says.
The agency notes that the trend toward computer-driven vehicles began with such features as antilock brakes, electronic-stability control and air bags, continuing today with automatic-emergency braking, forward-crash warning and lane-departure warnings.
“If no human occupant of the vehicle can actually drive the vehicle, it is more reasonable to identify the driver as whatever (as opposed to whoever) is doing the driving. In this instance, an item of motor vehicle equipment, the SDS, is actually driving the vehicle,” according to the chief counsel.
There are limits to NHTSA’s interpretation of FMVSS, the agency notes. It cannot make substantive changes to the statutory or regulatory regime or the clear language of a provision.
“An interpretation describes an agency’s view of the meaning of an existing statute or regulation,” according to the chief counsel. “It can make sense of the overall legal framework and provide clarity for regulated entities and the public.”
In its letter, NHTSA’s chief counsel says that a steering wheel is not expressly required by any FMVSS.
“We agree with Google that, as described, the SDV appears to be designed to self-cancel the turn signal operating unit as NHTSA would have intended had vehicles without steering wheels been available when FMVSS No. 108 was developed,” according to the letter.
However, NHTSA notes that the fact the SDS may be programmed to cancel the turn signal and switch headlamp beams on does not overcome the plain language of the standard.
“We understand Google’s argument that in the case of the SDV, manual cancelation of the turn signal operating unit by a human occupant could interfere with decisions already made by the SDS in ways that could affect safety,” according to the letter. “However, this is an issue that cannot be addressed through interpretation alone.”
Addressing FMVSS No. 111, Rear Visibility, the chief counsel says this contains requirements for rear-visibility devices and systems. Vehicles must have external and internal rear-view mirrors that provide the driver with certain fields of vision around and behind the vehicle, he says.
“Google asks that NHTSA interpret these provisions as requiring the specified view be provided to the SDS rather than to the human occupant. Google further requests that the vehicle would be deemed compliant if the SDS receives sensor input at least equivalent to the images a driver would be able to view through mirrors and a rear-visibility system, meeting the field of view and other performance requirements of the standard,” Hemmersbaugh says.
Because NHTSA is interpreting the driver and operator as the SDS, it agrees that the visibility images must be provided to the SDS. However, the chief counsel says that NHTSA has no way at this time of verifying Google’s compliance with this interpretation.
“Thus, if Google certified its compliance with these provisions consistent with this interpretation, NHTSA would be unable to conduct confirmatory testing to satisfy ourselves that such certification was valid,” Hemmersbaugh says.
Until appropriate performance criteria and test procedures for evaluating whether the sensor input received by the SDS provides enough information, NHTSA says it cannot interpret Google’s SDV as complaint with these standards and requirements.
“This would need to be undertaken through rulemaking,” the chief counsel says. “NHTSA may also consider as a part of such rulemaking whether there is a benefit to conveying this information to human occupants in the case of vehicle designs like Google SDV. Google may wish to petition the agency for an exemption from these provisions, in which it could seek to demonstrate that its SDV would provide an equivalent level of safety to that provided by compliance with the FMVSS.”
NHTSA also addresses Google’s questions about FMVSS No. 104, Windshield Wiping and Washing Systems.
“The agency would need to consider whether to evaluate through rulemaking whether a vehicle design without a mechanism by which humans can drive it even needs windshield wipers for safety purposes. In the interim, Google may wish to petition for exemption from this provision,” Hemmersbaugh says.
NHTSA’s response is addressed to Chris Urmson, director of self-driving car project for Google.
To read NHTSA’s entire response, click here.